The present invention relates to a rolling bearing and more particularly to a rolling bearing which exhibits excellent bearing rotary properties, suppressed fretting abrasion even upon repeated rocking motion due to external vibration during transportation and a drastically improved acoustic durability when used in a spindle, which is one of the constituent components of various motors for data recording device, household electric appliances, etc.
As lubricants or greases to be enclosed in a rolling bearing for spindle motor for data recording devices in computer or household electric appliances there have been developed various compounds depending on their purposes. In recent years, development has been made aiming at the reduction of torque meeting the demand for energy saving and the improvement of acoustic durability for improving the reliability.
Since data recording devices, household electric appliances, etc. are normally transported by truck with a rolling bearing mounted thereon, the rolling bearing is often subject to repeated rocking during transportation that causes fretting abrasion. Thus, rolling bearings have been also required to have an excellent fretting abrasion resistance.